Urbanization is a powerful force in shaping landscapes worldwide, and nowhere is this transformation more evident than in Las Vegas, Nevada. Over recent decades, Las Vegas has experienced rapid urban growth. In 1950, its population was 34,828, but by 2024, it had surged to an estimated 2,952,756 residents (World Population Review, 2024). This extreme growth has been fueled by factors like population expansion, tourism, and infrastructural development.
In addition to urbanization, the region faces unique challenges related to water resources, particularly its reliance on the Colorado River and the critical reservoir of Lake Mead. As the city continues to grow, the demand for these vital water sources will only increase, and is made worse by the surrounding arid desert environment. The United States Bureau of Reclamation predicts that Lake Mead’s water level will drop to 1,056.19 feet by December 2024 and further to 1,044.33 feet by December 2025. This is very close to the lowest recorded level since it was filled at 1,041.71 feet above sea level (USBR, 2024).
I wanted to get two Landsat images spanning a wide time gap. From USGS Earth Explorer I downloaded a Landsat 7 image from October 1999, and a Landsat 9 image from January 2024. I added the bands into an R script and made sure they were projected to the same coordinate system (NAD83). I then copied and cropped them to Las Vegas and Lake Mead.
#carterquesenberry final project
library(terra)
#add landsat 7 (1999) data:
landsat7_blue <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LE07_L1TP_039035_19991008_20200918_02_T1/LE07_L1TP_039035_19991008_20200918_02_T1_B1.TIF")
landsat7_green <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LE07_L1TP_039035_19991008_20200918_02_T1/LE07_L1TP_039035_19991008_20200918_02_T1_B2.TIF")
landsat7_red <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LE07_L1TP_039035_19991008_20200918_02_T1/LE07_L1TP_039035_19991008_20200918_02_T1_B3.TIF")
landsat7_nir <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LE07_L1TP_039035_19991008_20200918_02_T1/LE07_L1TP_039035_19991008_20200918_02_T1_B4.TIF")
landsat7_swir <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LE07_L1TP_039035_19991008_20200918_02_T1/LE07_L1TP_039035_19991008_20200918_02_T1_B5.TIF")
#combine all bands:
landsat7 <- c(landsat7_blue, landsat7_green, landsat7_red, landsat7_nir, landsat7_swir)
#reproject to NAD83 crs:
landsat7 <- project(landsat7, "EPSG:4269")
#add landsat 9 (2023) data:
landsat9_blue <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LC09_L1TP_039035_20231213_20231213_02_T1/LC09_L1TP_039035_20231213_20231213_02_T1_B2.TIF")
landsat9_green<- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LC09_L1TP_039035_20231213_20231213_02_T1/LC09_L1TP_039035_20231213_20231213_02_T1_B3.TIF")
landsat9_red <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LC09_L1TP_039035_20231213_20231213_02_T1/LC09_L1TP_039035_20231213_20231213_02_T1_B4.TIF")
landsat9_nir <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LC09_L1TP_039035_20231213_20231213_02_T1/LC09_L1TP_039035_20231213_20231213_02_T1_B5.TIF")
landsat9_swir1 <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LC09_L1TP_039035_20231213_20231213_02_T1/LC09_L1TP_039035_20231213_20231213_02_T1_B6.TIF")
landsat9_swir2 <- rast("/Users/carterqberry/R Studio/Final Project/Landsat/LC09_L1TP_039035_20231213_20231213_02_T1/LC09_L1TP_039035_20231213_20231213_02_T1_B7.TIF")
#combine all bands:
landsat9 <- c(landsat9_blue, landsat9_green, landsat9_red, landsat9_nir, landsat9_swir1, landsat9_swir2)
#reproject to NAD83 crs:
landsat9 <- project(landsat9, "EPSG:4269")
Here is what the Landsat images look like:
#set las vegas extent:
vegas_extent <- as.polygons(ext(c(-115.4, -114.95, 36, 36.32)))
crs(vegas_extent) <- "EPSG:4269"
vegas_extent <- project(vegas_extent, "EPSG:4269")
#crop landsat 7 to vegas extent:
landsat7_vegas <- crop(landsat7, vegas_extent)
plotRGB(landsat7_vegas, r=3, g=2, b=1, stretch = "linear", main="Landsat 7 Image of Las Vegas", mar = 2)
#crop landsat 9 to vegas extent:
landsat9_vegas <- crop(landsat9, vegas_extent)
plotRGB(landsat9_vegas, r=3, g=2, b=1, stretch = "linear", main="Landsat 9 Image of Las Vegas", mar = 2)
#set lake mead extent:
mead_extent <- as.polygons(ext(c(-114.95, -113.85, 35.9, 36.6)))
crs(mead_extent) <- "EPSG:4269"
mead_extent <- project(mead_extent, "EPSG:4269")
#crop landsat 7 to mead extent:
landsat7_mead <- crop(landsat7, mead_extent)
plotRGB(landsat7_mead, r=3, g=2, b=1, stretch = "linear", main="Landsat 7 Image of Lake Mead", mar = 2)
#crop landsat 9 to mead extent:
landsat9_mead <- crop(landsat9, mead_extent)
plotRGB(landsat9_mead, r=3, g=2, b=1, stretch = "linear", main="Landsat 9 Image of Lake Mead", mar = 2)